The arguement on whether to go to space or not is an interesting one. It's similar to whether we should just send robots out to space or make human settlement somewhere in space. Today, people laugh at the thought of the flat earth. Will people tomorrow laugh at whether we thought going to space was the answer to everything? Or, developing nano-manufacturing? Should we pray to god, or figure out the universe scientifically?
Another example comes from the history of mathematics. The Greek seem to have gotten lot's of mathematics from the Babylonians(pythagorean theorem . . . although not proved in near generality as the Greeks did . . . and lots of other pieces of mathematics but not quite proved;pythagorean triplets, quadratic equation, all angles in a semi-circle are right angles . . . the Greeks attribute this in full to Thales . . . ; well, maybe this isn't that much mathematics). The Greeks chose to geometrize the little algebra they learned from the Babylonians instead of developing an adequate number system(the Greeks even came up with a geometric real number system from Eudoxus; this was preserved in Euclid's Elements book five). This made for a cumbersome mathematics that couldn't see past the third dimension(or third degree equations; Archimedes solved at least one cubic using conics). Pretty soon, there was no new mathematics to discover and people turned to creating one religion(one ring to rule them all) christianity. One church father Tertullian said, "what does Athens have to do with Jerusalem?"
I feel like there's something here that I don't have an abstract description of yet. It reminds me a little bit of how you could read a book after it being a long time, and you notice details and meaning in it that you didn't pick up before.
Part of what I've tried to push here on this blog is that the general viewpoint is desirable; and that mathematics is the most general viewpoint. I know that Eric Drexler has clearly gone over to nanomanufacturing as the most general technological development and the only practical way to space(a desirable but not a necessary goal). Robert Zubrin has said that nanomanufacturing is "unobtaineaum", and we should settle mars now. Meanwhile, the global warming is heating up(there's been a recent calculation by the way that if you raise everybody to a wealthy state of being, you'd raise the temperature of the earth's atmosphere by three degrees - an arguement for space expansion as a necessary part of the human adventure so to speak). Tick tock, tick tock - what's right; what's wrong!?
Well, I still say going to space in important for freeing the mind from any social group that has decided to not question anymore.